Fuel pressure switch



Aug. 17, 1943. A. SATTERLEE 2,327,059

FUEL PRESSURE SWITCH Filed July 27, 1942 v 53 39 a 29 46 w Patented 171943 FUEL PRESSURE SWITCH Howard a. Satteriee, Bryan, Ohio, assignor toThe Arc Equipment Corporation, Bryan, Ohio,

n. corporation of Ohio Application July 27, 1942, Serial No. 452,486

12Claims.

My present invention relates to a fuel pressure switch such as used in afuel system for multiple fuel tanks of an aeroplane or the like, asdisclosed in the copending application of David Samiran, Serial No.370,027, filed December 13,

1940. One object of the invention is to provide a fuel I operated deviceby the mere screwing of a subhousing thereon.

Still a further object is to provide the snap switch mechanism itself inthe form of three leaf spring devices so arranged that the switch isnormally biased to closed position by inherent resiliency of one of thethree blades, the switch mechanism including two simple adjusting screwsfor adjusting the switch to any particular pressure operated actuatingelement to which it is applied, and for adjusting the diiferential ofoperation of the-switch.

With these and other objects in view, my invention consists in theconstruction, arrange ment and combination of the various parts of mydevice whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in the claims andillustrated in theaccompanying drawing in which:

Figure 1 is a sectional view showing my fuel pressure switch mounted ona pressure operated actuating device, the entire structure .being' shownsubstantially double actual size;

Figure2isaviewofaportionofFigurei showing the switch in open circuitposition, whereas it is shown in closed circuit position in Figure 1; Y

Figure 3 is a perspective view of the three switch blades of the snapswitch mechanism; and

Figure 4 is a plan view of a supporting disk for the pressure operatedactuating element that operates the switch mechanism.

0n the accompanying drawing I have used the reference numerals. l0 andI! to indicate two parts of a housing. The parts ill and i2 may besecured together as by a plurality of cap screws I 3.

The housing ill-42 has therein a pressure operated actuating element itin the form of a hardened rivet pressed into a sleeve Ii.

sleeve I! has a reduced threaded portion l8 extending through a sealingcap I! and a diaphragm I8. The diaphragm I8 is shown of two thicknessesof neoprene or the like, and may have a thin disk of brass or othersuitable metal (not illustrated) between them. The diaphragm I8 isreinforced on .opposite sides by disks IS.

The sealing cap I'I may be of neoprene or the like and tightly engagesover-a knob-like bead 20 of a partition member 2| so as to seal thecavity in the housing part III surrounding the cap I! from atmospherethrough a bore 22 for the sleeve I5. A retainer nut 23 is threaded onthe portion 16 of the sleeve ii to retain the parts [1, I8 and i9tightly sealed thereon.

A chamber within the housing part I2 is adapted to be subjected topressure from a fuel line or the like, as shown in the Samiranapplication.

Such fuel line is connected to a threaded opening 24 which communicatesby means of a port 25 with the interior of the housing part I2. A spring26 in the interior of the housing part 10 opposes the pressureintroduced through the port 25.

For adjusting the diaphragm i 8 for response at various pressureswithout adjusting the spring 26, a trimmer spring 21 is utilized, whichis mounted in opposition to the spring 26. The trimmer spring 21 isbacked by a washer 28, the position of which may be adjusted by means ofan adjusting screw 29. A lock nut 30 is provided for the screw 29 andthe head of the screw is covered by a cap 3! screwed against a gasket 32to thereby seal off the adjusting screw 29 from atmosphere. The sleeveI5 is supported for axial movement by a disk l5 retained in position byscrews It. The disk has slots I! to reduce its resistance to bowing.

A threaded opening 33 is illustrated, connected by a, port 34, a sleeve35 and a port 36,

with the interior of the housing part It. Thisv may be open toatmosphere so that a change in altitude is compensated for byatmospheric pressure on the back of the diaphragm [8. Where the enginehas a supercharger, the opening 33 may be connected with thesupercharger to impose the pressure thereof on the back of thediaphragm.

. The switch mechanism which I have provided for association with thepressure operated actuating element It will now be described. Itcomprises a base 31 of'suitable insulating 7 material and positionedagainst one end of a threaded sleeve portion 38 of the housing Iii-l2.

The It is retained in this position by a sub-housing 39 threaded on thesleeve portion 38, and, I

in turn, provided witha threaded sleeve portion 49 for connection with afitting at the end of a circuit wire carrying cable. 39 is utilized tolock the sub-housing 39 on the base 31. The set screw is to be retainedagainst loosening by a safety wire 39 connecting one of the cap screwsi3 and the set screw together.

Circuit connecting prongs 4i and 42 are mounted on the base 31 byriveting or the like, and serve to connect a pair of brackets B and B"against the inner surface of the base 31. The bracketB is L-shaped,having an anchored leg 43 and a pivot leg 44. The bracket 3" is a shortbar carrying a stationary contact 53. A third bracket 3' has legs 45,4B, 41 and 48, the leg 45 being bifurcated. The leg 45 is anchored tothe base 31 by a pair of rivets 45 The bracket B" is anchored to thebase 31 by the pron 42. The leg 48 is also bifurcated to form a pair ofpivot portions, asillustrated in Figure 3.

The pivot legs 44 :and 48 have pivotally associated therewith a togglespring T comprising a center leg 49 and a pair of side legs 50. Thecenter leg 49 has an opening 5| to receive the pivot leg 44, whereas theterminal ends of the side legs 59 coact with the pivot legs 48. Themanner of coaction is knife edges with V-shaped notches of the usual,well-known type.

The toggle spring T carries a movable contact 52 for coaction with astationary contact 53 carried bythe leg 45 of the bracket .8. Adifferential adjusting screw 54 is carried by a boss 55 riveted to theleg 41 of the bracket B,

A set screw and an adjusting screw 58 is similarly carried by a boss 51.The adjusting screw 56 is to take care of manufacturing tolerancesencountered .in the fabrication of the pressure operated actuatingdevice whereby the switch mechanism may be operated at the proper pointin the leg 41.

The bracket B is made of spring material so shaped as to be biasedtoward closed circuit position, as shown in Figure 1, whereby thediaphragm l8 when sprung toward the left will open the circuit throughthe switch against such bias. The switch blades 49 and 50 are bowedbecause of being assembled under tension with the blade 49 pullingupwardly on the pivot arm 44 and the blades 59 pushing downwardly on thepivot arms 48 in Figure 1. Accordingly, the pressure introduced throughthe port 25 against the diaphragm l8 may bow the diaphragm toward theleft until a'balanced center position is reached, whereupon the pivotpoint at the junction of its travel. The bosses 55 and 51 are riveted toconnections and anchoring the brackets B and B' with respect to the base31. The differential of operation of the switch may be readily adjustedby unscrewing the screw 54, thereby reducing the throw of the contact 52and decreasing the differential of operation, or screwing the screw 54inwardly relative to the boss 55 for increasing the differential. Thescrew 56 may be readily adjusted for the switch to operate from oneposition to the other at the proper position of the diaphragm 18.

Some changes may be made in the construction and arrangement of theparts of my device without. departing from the real spirit and purposeof my invention, and it is my intention to cover by my claims anymodified forms of structure, or use of mechanical equivalents, which maybe reasonably included within their scope.

I claim as my invention:

1. In a fuel pressure switch, a housing having a threaded sleeveportion, a pressure operated actuating element therein located at theaxis of the sleeve portion, a sub-housing threaded on said sleeveportion, a switch unit including a base of insulating material confinedin position between the end of said sleeve portion and said sub-housingwhen said hub-housing is threaded on said sleeve portion, said switchunit further comprising a pair of circuit connecting elements projectingoutwardly relative to said base, and snap switch m hanism on the innersurface of said base comp ising a pivot bracket secured to said base atone of said circuit connecting elements, a second pivot bracket securedto said base at the other of saidcircuit connecting elements andcarrying astationary contact, a toggle spring connected between the twopivot brackets and carrying a movable contact, one of said pivotbrackets having a movable portion constrained by the inherent resiliencyof the-bracket to engage said pressure operated actuating element to bemoved by the actuating element as it moves, the movement of said lastbracket effecting shifting of the pivot point thereof and thereby of;said toggle spring across center to change the circuit controllingposition of the switch, means for adjusting the differential of saidswitch comprising an adjustable stop on said last bracket limiting thedegree of movement of said toggle spring,

and means to adjust the position of said last bracket with relation tosaid pressure operated actuating element comprising a screw threaded insaid last bracket for contact with said pressure operated actuatingelement.

2. A fuel pressureswitch of the character disclosed comprising ahousing, a pressure operated actuating element therein, a sub-housing onsaid 48 with 59 passes across center relative to the pivot point at thejunction of 49 with 5|. Thereupon, the switch snaps to the open positionof Figure 2, whereas reduction of pressure against the diaphragm i8 willeventually permit the switch to be moved back to a balanced centerposition. Here, again, the parts cross center,-

and the switch snaps to the closed position.

From the foregoing disclosure it is obvious that I have provided a snapswitch unit which housing, a switch unit including a base, a'pair ofcircuit connecting prongs projecting outwardly therefrom and snap switchmechanism on the inner surface of said base, said snap switch mechanismcomprising a pair of pivot brackets, and a toggle spring comprising acontact carrying blade and a toggle blade, said contact carrying bladebeing pivotally engaged with one of'said brackets and said toggle bladebeing engaged with the other of said brackets, said 'other brackethaving a stationary contact for coaction therewith, said pressureoperated actuatingelement being operable to move said other bracket andthereby said toggle spring blade.

3. In a pressure switch, a housing having a threaded sleeve portion, apressure operated actuating element therein located at the axis of thesleeve portion, a sub-housing threaded on said sleeve portion, a switchunit including a base confined in position between the end of saidsleeve portion and said sub-housing when said sub-housing is threaded onsaid sleeve portion, said switch unit further comprising a pair ofprongs projecting outwardly relative to said base, and snap switchmechanism on the inner surface of said base comprising a pivot bracketsecured to said base at one of said prongs, a second pivot bracketsecured to said base at the other of said prongs and carrying astationary contact, a toggle spring connected between the two pivotbrackets and carrying a movable contact, one of said pivot bracketshaving a movable portion constrained by the inherent resiliency of thebracket to engage said pressure operated actuating element to be movedby the actuating element as it moves, the movementof said last bracketefiecting shifting of the pivot point thereof and thereby-of said togglespring across center to change the circuit controlling position of theswitch, and means for adjusting the differential of said switchcomprising an adjustable stop on said last bracket limiting the degreeof movement of said toggle spring.

4. A fuel pressure switch comprising a housing, a pressure operatedactuating element therein, a switch unit including a base mounted onsaid housing-said switch unit further comprising a pair of circuitconnecting elements projecting outwardly relative to said base, and snapswitch mechanism on the inner surface of said base, said snap switchmechanism comprising a pair of pivot brackets, a toggle spring spanningsaid brackets and including a contact carrying blade, said pressureoperated actuating element being operable to snap said toggle springfrom one circuit controlling position to another, and means foradjusting the difierential of operation of said toggle spring comprisingan adjustable stop on one of said brackets limiting the degree ofmovement of said toggle spring.

5. In a-fuel pressure switch, a housing having a threaded sleeveportion, a pressure operated actuating element therein located at theaxis of the sleeve'portion, a sub-housing threaded on said sleeveportion, a switchunit including a base confined in position between theend of said sleeve portion and said sub-housing when said sub-housing isthreaded on said sleeve portion, said switch unit further comprising apair of circuit connecting elements projecting outwardly relative tosaid base, and snap switch mechanism on the inner surface of said basecomprising a pivot bracket secured to said base at one of said circuitconnecting elements, a second pivot bracket secured to said base at theother of said circuit connecting elements and carrying a stationarycontact, a toggle spring connected be tween the two pivot brackets andcarrying a' movable contact, one of said pivot brackets having a movableportion constrained by the inherent resiliency of the bracket to engagesaid pressure operated actuating element to be moved by the actuatingelement as it moves, the movement of said last bracket effectingshifting of the pivot point thereof and thereby of said toggle springacross center to change the circuit controlling position of the switch,and means to adjust the position of said last bracket with relation tosaid pressure operated actuating element comprising a screw threaded insaid last bracket for contact with said pressure operated actuatingelement.

6. In a fuel pressure switch, a housing having a. threaded sleeveportion, a pressure operated actuating element therein located at theaxis of the sleeve portion, a sub-housing threaded on said sleeveportion, a switch unit including a base of insulating material confinedin position between the end of said sleeve portion and said subhousingwhen said sub-housing is threaded on said sleeve portion, said switchunit further comprising a pair of circuit connecting elements projectingoutwardly relative to said base, and snap switch mechanism on the innersurface of said base and operated by said pressure operated actuatingelement.

7. A switch of the character disclosed comprising a housing and anactuating element therein, a switch unit incl ding a base, a pair ofprongs projecting outwardl relative to said base, and

snap switch mechanism on the inner surface of said base, said snapswitch mechanism comprising a pair of pivot brackets one of whichextends across said base and terminates adjacent the other of saidbrackets, said pressure operated actuating element being engageable withsaid one of said brackets to operate said toggle spring to effectopening and closing of a circuit controlled by said switch contacts.

8. A fuel pressure switch comprising a: housing, a pressure operatedactuating element therein, a switch unit including a base mounted onsaid housing, said swiikzh unit further comprising a pair of circuitconnecting elements projecting outwardly relative to said base, and snapswitch mechanism on the innersurface of said base, said snap switchmechanism comprising a pair of pivot brackets, a toggle spring includinga contact carrying blade, said pressure operated actuating element beingoperable to snap said toggle spring from one circuit controllingposition to another, and means for adjusting the position of actuationof said snap switch mechanism relative to said pressure operatedactuating element.

9. In a pressure switch, a housing having a threaded sleeve portion, apressure operated actuating element therein located at theaxis of saidsleeve portion, a sub-housing threaded on said sleeve portion, a switchunit including a base confined in position between the end of saidsleeve portion and said sub-housing when the sub-housing is threaded onsaid sleeve portion, said switch unit further comprising a pair ofcircuit controlling elements projecting outwardly relative to said base,and snap switch mechanism on the inner surface of said base, said snapswitch mechanism comprising a pair of pivot brackets, one beingangle-shaped and the other being substantially rectangular shaped, oneleg of said first bracket being secured to said base by one of saidcircuit controlling elements, and one end leg of the other bracket beingsecured to said base by the other of said elements, the other leg ofsaid first bracket constituting apivot point, and a toggle springcomprising a contact carrying blade and a pair of toggle blades onopposite sides thereof, said contact carrying blade being pivotallyengaged withsaid other leg of said first bracket and the ends of saidtoggle blades being engaged with a pivot portion of said other bracketat the end thereof opposite the anchored end, said other bracket havinga stationary contact for coaction with. said contact carrying blade,said pressure operated actuating element being engageable with saidother bracket, said other bracket being under tension to effect suchengagement whereby movement of the pressure operated actuating elementin opposition to the bias of said other bracket shifts the pivot pointcarried thereby across center relative to said toggle spring to effectopening of said switch contacts which are normally closed due to theinherent resiliency of said other bracket.

10. In a pressure switch of the character described, a housing, apressure operated actuating element therein, a sub-housing mounted onsaid housing, a switch unit including a base confined in positionbetween said sub-housing and said housing, said switch unit furtherincluding snap switch mechanism comprising a Pivot bracket secured tosaid base, a second pivot bracket secured to said base and carrying astationary contact, and a toggle spring connected between the two pivotbrackets, and carrying a movable contact, one of said pivot bracketshaving a movable portion constrained by the inherent resiliency of thebracket to engage said pressure operated.

a base, and snap switch mechanism thereon, said snap switch mechanismcomprising a pair of pivot brackets secured to said base, a stationarycontact carried by one of said brackets, a toggle spring connectedbetween the two pivot brackets and carrying a movable contact, saidpressure operated actuating element being adapted to I move a portion ofone of said brackets as the actuating'element moves, the movement ofsaid last bracket effecting shifting of the pivot point thereof andthereby of said toggle spring across center to change the circuitcontrolling position of the switch, and means for adjusting thedifferential of said switch and the position of said bracket withrelation to said pressure operated actuating element.

12. A pressure switch of the character disclosed comprising a housing, apressure. operated actuating element movably mounted therein, asub-housing threaded on said housing, a switch unit confined in positionbetween said sub-housing and said housing, said switch unit includingsnap switch mechanism comprising a pair of pivot brackets, and a togglespring operated by said pressure operated actuating element engaging oneof said pivot brackets, and means for adjusting the position ofactuation of said snap switch mechanism relative to said pressureoperated actuating element comprising an adjusting screw carried by oneof said pivot brackets.

HOWARD A. SATTERLEE.

V. DISCLAIMER v 2,327,069 .Howard A. Satterlee, Bryan, Ohio. FUELPRESSURE Swrrcn. Patent dated Aug. 17, 1943. -Diso1aimer filed Sept. 26,1945, by the inventor;-

the assignee, The Aro Equipment Corporation, joining in andapproving.Hereby. enters this disclaimer to claims 4 and 7 in said specification.

[Ofiic'ial Gazette October'fSO, 1945.]

DISCLAIMER 2,327,069 .-Howard A. Satterlee, Bryan, Ohio. FUEL PRESSURESwrrcn. Patent dated Aug. 17, 1943. Disclaimer filed Sept. 26, 1945, bythe inventor;-

the assignee, The Aro Equipment Corporation, joining in and'approving.Hereby enters this disclaimer to claims 4 and 7 in said specification.

'[Ofiic'ial Gazette October'80, 1945.]

